Sqrt(x)

class Solution {public:    int mySqrt(int x)     {         long long low=0;        long long high=x;        long long result=0;        while(low<=high)        {            long long mid=low+(high-low)/2;            result=mid*mid;            if(result==x)                return mid;            else if(result>x)                high=mid-1;            else                low=mid+1;        }        return high;    }};